I have written this indicator: VWAP@Time Z-score .
Which I have published on PRC but it’s still not available at that precise moment (so meanwhile I post below the code):

// VWAP@Time intraday Z-Score
// 17.11.2020
// Daniele Maddaluno
//
// startTime = 80000
// endTime = 153000
// smoothZscore = f
// stdev = 2
 
once posLev1=+stdev/2
once negLev1=-stdev/2
once posLev2=+stdev
once negLev2=-stdev
 
if opentime < startTime or opentime > endTime then
	n = 0
	zscoreT = 0
 
	priced  = 0
	shared  = 0
	summ = 0
 
	vwap = close
	vwapstd = 0
else
	n = n + 1
	// This if has been added just for plot reasons
	if n <= 1 then
		zscoreT = 0
	else
		zscoreT = 190
	endif
 
	priced = priced + (totalprice*volume)
	shared = shared + volume
 
	if shared>0 then
		vwap = priced/shared
 
		summ = summ + square(totalprice - vwap)
		vwapstd = sqrt(summ / n)
	endif
 
endif
 
if smoothZscore then
	zscore = average[3]((close-vwap)/vwapstd)
	else
	zscore = (close-vwap)/vwapstd
endif
 
if zscore>=posLev2 then
	drawcandle(posLev2, posLev2*1.25, posLev2, posLev2*1.25) coloured(255, 0, 0, 100) bordercolor(0, 0, 0, 0)
endif
if zscore<=negLev2 then
	drawcandle(negLev2, negLev2*1.25, negLev2, negLev2*1.25) coloured(0, 255, 0, 100) bordercolor(0, 0, 0, 0)
endif
 
// Manage the coloring of vwap mid line
if zscore > zscore[1] then
	dwapR = 0
	dwapG = 128
	dwapB = 192
else
	dwapR = 255
	dwapG = 0
	dwapB = 0
endif
 
return zscore coloured(dwapR, dwapG, dwapB, zscoreT) style(line, 2) as "Z-score", posLev1 coloured(168, 168, 168) style(line, 2) as "Level +stdev/2", posLev2 coloured(210, 210, 210) style(line, 2) as "Level +stdev", negLev1 coloured(168, 168, 168) style(line, 2) as "Level -stdev/2", negLev2 coloured(210, 210, 210) style(line, 2) as "Level -stdev", 0 coloured(168, 168, 168) style(dottedline) as "Level 0"

I have noticed that sometimes it has a strange behaviour that I didn’t had on PRT v10.
Using this indicator, when horizontally scrolling at the barindex+1 bar (I mean the bar next the current one) the indicator completely disappears…
Values in the “current” bar seems to be computed correctly…
The main problem is that sometimes works, sometimes doesn’t, so I could not address any clear reason of the fault…
I don’t think it’s linked to the indicator because I’m pretty sure that I have never had that problem on v10 (but I can be wrong)…

I have attached a video to show what I meant.
PRT v11.1 – 18.0_202 + IG (last update on 25 nov 2020)